‘Sea level in the Arctic is falling’–Sea level is a surprisingly complicated thing

Objection: According to the latest state-of-the-art satellite measurements from over the Arctic, sea levels are falling! Guess all that ice isn’t melting after all.

Answer: Yes, a new study using Europe’s Space Agency’s ERS-2 satellite has determined that over the last 10 years, sea level in the Arctic Ocean has been falling at an average rate of about 2 mm/year. This is very new and very interesting news, though it is preliminary and not published in any peer-reviewed journals yet. But even if these results hold up to time and scrutiny, it is not evidence that globally sea levels are not rising, because they are.

Local sea levels are subject to many influences including: wind and ocean currents that can “pile up” the ocean water locally, temperature anomalies like El Niño, local gravity wells of ice sheets and land masses, and regional salinity levels that alter the water’s density. Measurement of these levels is further complicated by changes in land height as the Earth’s crust moves up or down from tectonic motion and rebounds after long and recently ended glaciation, although these complications are avoided by using satellite measurements.

So in short, this is undoubtedly of interest to specialists in several fields, but it does not in any way alter the Global Climate Change picture.

Stories in this series:

(Part of the How to Talk to a Climate Skeptic guide) Objection: Despite what the computer models tell us, there is actually no evidence of significant global warming. Answer: Global warming is not an output of computer models; it is …

(Part of the How to Talk to a Global Warming Skeptic guide) Objection: CO2 levels are recorded on top of Mauna Loa ... a volcano! No wonder the levels are so high. (image courtesty of Global Warming Art)

(Part of the How to Talk to a Global Warming Skeptic guide) Objection: The apparent rise of global average temperatures is actually an illusion due to the urbanization of land around weather stations, the Urban Heat Island effect.